Rough-cut capacity planning with production constraints and dynamic bottleneck considerations

Abstract

To assess the sufficiency of a plurality of machines for processing a number of items, machine availability information indicative of availability of the machines for processing the items, machine capacity information indicative of a capacity of each of the machines for processing the items, and machine preference information indicative of a preference of each of the machines for processing the items are obtained. A capacity constraint, such as an upper limit of items to be processed during a time interval, is determined based on the machine availability information, machine capacity information and machine preference information. At least some of the machines are allocated to process at least some of the items based on the machine availability information, machine capacity information and machine preference information, subject to the capacity constraint. The resulting rough-cut capacity plan may be used to balance available capacity against required capacity.

1. A method of assessing a sufficiency of a plurality of work centers for processing a plurality of jobs during a time interval, each work center having a group of machines for performing an operation, each job having a job priority and including one or more operations to be performed upon a set of items associated with the job, the items of the set being like items, each machine having a preference level for processing the items associated with each job, said preference level being one of a range of machine preference levels, the method comprising:
 determining which jobs of said plurality of jobs have an operation that is associated with a work center having an available machine whose preference level for processing the items associated with the job matches a current machine preference level, said current machine preference level having been selected from said range of machine preference levels in decreasing preference order, said determining resulting in a set of candidate jobs; 
 selecting a highest priority job from said set of candidate jobs, said selecting resulting in a selected job, the items associated with said selected job being referred to as selected items; 
 at each work center associated with an operation of the selected job, allocating one or more machines having either said current machine preference level or a lower machine preference level in respect of the selected items to process a chosen number of units of the selected items, said allocating of machines being performed in decreasing order of machine preference level in respect of the selected items; 
 prior to said allocating:
 calculating, for each work center associated with an operation of the selected job, a maximum number of units of the selected items that the work center is capable of processing during said time interval, said calculating being based on availability of machines having said current machine preference level or a lower machine preference level in respect of the selected items and on a processing rate of said machines when processing the selected items, said calculating resulting in a set of numbers, each of said numbers being a maximum number of units capable of being processed by a work center; and 
 choosing a minimum value from said set of numbers, said minimum value defining a bottleneck number of units of the selected items to be processed during the time interval; and 
 
 outputting a rough-cut capacity plan indicative of said allocating, 
 wherein the machine preference level of each machine for processing the items associated with a job is dependent upon the items to be processed, 
 and wherein said chosen number of units is said bottleneck number of units. 
 
     
     
       2. The method of  claim 1  further comprising, prior to said determining, identifying jobs from said plurality of jobs for which no machine has yet been allocated to perform any of the one or more operations associated with the job, said identifying resulting in identified jobs, and wherein said determining is limited to said identified jobs. 
     
     
       3. The method of  claim 2  further comprising repeating said identifying, said determining, said selecting, said calculating, said choosing and said allocating until either a machine has been allocated to perform each operation of each one of said plurality of jobs or until said allocating cannot be performed for an operation of one of said plurality of jobs. 
     
     
       4. The method of  claim 1  wherein said job priority is determined based on one or more of an importance of a customer associated with said job, an importance of a product associated with said job, or a deadline for completing said job. 
     
     
       5. The method of  claim 1  further comprising processing said items in accordance with said rough-cut capacity plan. 
     
     
       6. A machine-readable medium comprising code which, upon execution by a processor of a computing device, causes said computing device to assess a sufficiency of a plurality of work centers for processing a plurality of jobs during a time interval, each work center having a group of machines for performing an operation, each job having a job priority and including one or more operations to be performed upon a set of items associated with the job, the items of the set being like items, each machine having a preference level for processing the items associated with each job, said preference level being one of a range of machine preference levels, by:
 determining which jobs of said plurality of jobs have an operation that is associated with a work center having an available machine whose preference level for processing the items associated with the job matches a current machine preference level, said current machine preference level having been selected from said range of machine preference levels in decreasing preference order, said determining resulting in a set of candidate jobs; 
 selecting a highest priority job from said set of candidate jobs, said selecting resulting in a selected job, the items associated with said selected job being referred to as selected items; 
 at each work center associated with an operation of the selected job, allocating one or more machines having either said current machine preference level or a lower machine preference level in respect of the selected items to process a chosen number of units of the selected items, said allocating of machines being performed in decreasing order of machine preference level in respect of the selected items; 
 prior to said allocating:
 calculating, for each work center associated with an operation of the selected job, a maximum number of units of the selected items that the work center is capable of processing during said time interval, said calculating being based on availability of machines having said current machine preference level or a lower machine preference level in respect of the selected items and on a processing rate of said machines when processing the selected items, said calculating resulting in a set of numbers, each of said numbers being a maximum number of units capable of being processed by a work center; and 
 choosing a minimum value from said set of numbers, said minimum value defining a bottleneck number of units of the selected items to be processed during the time interval; and 
 
 outputting a rough-cut capacity plan indicative of said allocating, 
 wherein the machine preference level of each machine for processing the items associated with a job is dependent upon the items to be processed, 
 and wherein said chosen number of units is said bottleneck number of units. 
 
     
     
       7. The machine-readable medium of  claim 6  further comprising code which, upon execution by said processor of said computing device, causes said device to, prior to said determining, identify jobs from said plurality of jobs for which no machine has yet been allocated to perform any of the one or more operations associated with the job, said identifying resulting in identified jobs, and wherein said code for determining limits said determining to said identified jobs. 
     
     
       8. The machine-readable medium of  claim 7  further comprising code which, upon execution by said processor of said computing device, causes said device to repeat said identifying, said determining, said selecting, said calculating, said choosing and said allocating until either a machine has been allocated to perform each operation of each one of said plurality of jobs or until said allocating cannot be performed for an operation of one of said plurality of jobs. 
     
     
       9. The machine-readable medium of  claim 6  wherein said job priority is determined based on one or more of an importance of a customer associated with said job, an importance of a product associated with said job, or a deadline for completing said job. 
     
     
       10. A computing device comprising a processor and persistent storage memory in communication with said processor storing machine readable instructions which, upon execution by said processor, direct said device to assess a sufficiency of a plurality of work centers for processing a plurality of jobs during a time interval, each work center having a group of machines for performing an operation, each job having a job priority and including one or more operations to be performed upon a set of items associated with the job, the items of the set being like items, each machine having a preference level for processing the items associated with each job, said preference level being one of a range of machine preference levels, by:
 determining which jobs of said plurality of jobs have an operation that is associated with a work center having an available machine whose preference level for processing the items associated with the job matches a current machine preference level, said current machine preference level having been selected from said range of machine preference levels in decreasing preference order, said determining resulting in a set of candidate jobs; 
 selecting a highest priority job from said set of candidate jobs, said selecting resulting in a selected job, the items associated with said selected job being referred to as selected items; and 
 at each work center associated with an operation of the selected job, allocating one or more machines having either said current machine preference level or a lower machine preference level in respect of the selected items to process a chosen number of units of the selected items, said allocating of machines being performed in decreasing order of machine preference level in respect of the selected items; 
 prior to said allocating:
 calculating, for each work center associated with an operation of the selected job, a maximum number of units of the selected items that the work center is capable of processing during said time interval, said calculating being based on availability of machines having said current machine preference level or a lower machine preference level in respect of the selected items and on a processing rate of said machines when processing the selected items, said calculating resulting in a set of numbers, each of said numbers being a maximum number of units capable of being processed by a work center; and 
 choosing a minimum value from said set of numbers, said minimum value defining a bottleneck number of units of the selected items to be processed during the time interval; and 
 
 outputting a rough-cut capacity plan indicative of said allocating, 
 wherein the machine preference level of each machine for processing the items associated with a job is dependent upon the items to be processed, 
 and wherein said chosen number of units is said bottleneck number of units. 
 
     
     
       11. The computing device of  claim 10  wherein said code further causes said device to, prior to said determining, identify jobs from said plurality of jobs for which no machine has yet been allocated to perform any of the one or more operations associated with the job, said identifying resulting in identified jobs, and wherein said code for determining limits said determining to said identified jobs. 
     
     
       12. The computing device of  claim 11  wherein said code further causes said device to repeat said identifying, said determining, said selecting, said calculating, said choosing and said allocating until either a machine has been allocated to perform each operation of each one of said plurality of jobs or until said allocating cannot be performed for an operation of one of said plurality of jobs. 
     
     
       13. The computing device of  claim 10  wherein said job priority is determined based on one or more of an importance of a customer associated with said job, an importance of a product associated with said job, or a deadline for completing said job.